Systematic Investigation of the Synergistic and Antagonistic Effects on the Removal of Pyrene and Copper onto Mesoporous Silica from Aqueous Solutions

Abstract

Polycyclic aromatic hydrocarbons (PAHs) and heavy metals have attracted greater attention due to their single or complex risks. It is urgent to find useful methods to remove these two pollutants together. In this study, SBA15 and MCM-41 were selected and used for the simultaneous removal of pyrene and copper from aqueous solution. Batch experiments were conducted systematically by investigating the adsorption behavior and effects including kinetics, isotherms, ionic strength and pH effects. Experimental results showed that the Langmuir and pseudo-second-order model fitted the adsorption behavior better. The solution pH values and ionic strength affected the adsorption behavior greatly. Furthermore, the synergistic or antagonistic effects could be observed on the adsorption of pyrene and copper onto MCM-41 and SBA15, respectively. The synergistic and antagonistic effects of pyrene and copper onto mesoporous silica may be attributed to the size of pyrene–copper complex and the average pore size of adsorbents. With the higher pore size, the complex would be adsorbed onto the inner surface of MCM-41 which showed synergistic effect on the adsorption of pyrene and copper. This study shows new guidelines and insight into the study of adsorption behavior of PAHs and heavy metals from aquatic environments.

Morphological effects of spherical SiO2 and hexagonal mesoporous MCM‐41 nanoparticles in polyacrylonitrile mixed matrix membranes on the biofouling mitigation in short‐term filtration

“…Additionally, the rejection rates for BSA remained relatively consistent even with the addition of NPs to the casting solution. In all cases, the rejection rates exceeded 90%, indicating that the skin layer's pores are smaller than 11 nm, approximately the same size as the BSA molecule, which has a diameter of about 7.1 nm 30,50 . As a result, the majority of the BSA solution was prevented from passing through the membrane.…”

“…In all cases, the rejection rates exceeded 90%, indicating that the skin layer's pores are smaller than 11 nm, approximately the same size as the BSA molecule, which has a diameter of about 7.1 nm. 30,50 As a result, the majority of the BSA solution was prevented from passing through the membrane. Moreover, due to the sensitive nature of the BSA molecule and its surface charge changes at different pH, fabrication and filtration of BSA solution were performed at neutral pH.…”

“…Moreover, due to the sensitive nature of the BSA molecule and its surface charge changes at different pH, fabrication and filtration of BSA solution were performed at neutral pH. The isoelectric point for BSA protein, PAN, SiO 2 , and MCM-41 NP is negative at pHs above 7, [50][51][52][53] which causes an electrostatic repulsion force that is enhanced by increasing the NP content to the optimal amount; this force is intensified and leads to a reduction of membrane fouling in the filtration process. 27,51 For evaluating the effects of silica NP morphology on the antifouling performance of the MMM, the BSA solution was used as a protein model foulant.…”

Niclosamide encapsulated in mesoporous silica and geopolymer: A potential oral formulation for COVID-19

“…4 shows the zeta potential values for PG, MCM-41, SBA-15 and their NIC loaded NIC-PG, NIC-MCM-41, and NIC-SBA-15 nanohybrids measured in aqueous solution. It has been already known that the alteration in the pH values can influence the electrical conductivity on the surface of PG, MCM-41 and SBA-15 [ [40] , [41] , [42] ]. In an aqueous solution, the surface charge of PG was determined to be −44.36 ± 1.74 mV, which is higher than that of MCM-41(-39.33 ± 2.20 mV) and SBA-15(-39.26 ± 2.18 mV) respectively.…”